Hi,
Symblos browser haven't option "auto expand classes", but it may be useful (especially with unchecked "display bottom tree" ).
So I build C::B from sources and wrote this little path. It changes ExpandNamespaces member function: it will expand ns or classes with given depth level ( currently 2 ).
It's my first patch so I hope for your understanding : )
edit: patch updated, now it expand one level of namespace and one level of class, so it doesn't expand inner namespaces and classes.